Mixer, method of mixing raw material for powder metallurgy binder for injection moulding composition

A method of mixing raw material for powder metallurgy, for manufacturing a given type of ceramic feedstock pellets from a specific mixture including at least one inorganic powder of at least one oxide or cermet or metal or nitride type element or of at least one compound including at least one of said elements and at least one binder, according to which method:

• the mixture is added to a tank of a mixer including at least one mixing shaft and paddles and/or blades;
• the temperature of said tank and the content thereof is stabilized, by connecting a heat exchanger to a first heat exchange and mixing temperature maintenance circuit, close to a mixing temperature comprised between a lower temperature above which the specific mixture becomes a paste, and a higher temperature below which said specific mixture is maintained, and said heat exchanger, which includes a heater arranged to heat said tank or/and the content thereof, is controlled to a temperature comprised between said lower temperature (TINF) and said higher temperature (TSUP), said lower temperature (TINF) and said higher temperature (TSUP) being stored in a memory, for said specific mixture for a given type of ceramic, so that that said heater exchanges energy, in a first connection, with a first heat exchange and mixing temperature maintenance circuit, external to said tank, and wherein the thermal inertia of the first circuit is higher than that of said tank fully loaded with said specific mixture;
• said mixing shaft is set in motion at a speed lower than or equal to 700 revolutions per minute (rpm);
• said mixture is mixed until a compact homogeneous mass is obtained;
• the high temperature stabilisation of said tank (2) and the content thereof for which a reduction in temperature has been authorised is stopped at a temperature equal to or above a temperature (T5) which is specific to the mixture concerned and a characteristic of the compact homogeneous mass.